musicout.c

mepg 1 layer3软解码源代码,实现了对MP3文件的软件解码

/**********************************************************************
Copyright (c) 1991 MPEG/audio software simulation group, All Rights Reserved
musicout.c
**********************************************************************/
/**********************************************************************
 * MPEG/audio coding/decoding software, work in progress              *
 *   NOT for public distribution until verified and approved by the   *
 *   MPEG/audio committee.  For further information, please contact   *
 *   Chad Fogg email: <[e-mail]>                               *
 *                                                                    *
 * VERSION 4.1                                                        *
 *   changes made since last update:                                  *
 *   date   programmers                comment                        *
 * 2/25/91  Douglas Wong        start of version 1.0 records          *
 * 3/06/91  Douglas Wong        rename setup.h to dedef.h             *
 *                              removed extraneous variables          *
 *                              removed window_samples (now part of   *
 *                              filter_samples)                       *
 * 3/07/91  Davis Pan           changed output file to "codmusic"     *
 * 5/10/91  Vish (PRISM)        Ported to Macintosh and Unix.         *
 *                              Incorporated new "out_fifo()" which   *
 *                              writes out last incomplete buffer.    *
 *                              Incorporated all AIFF routines which  *
 *                              are also compatible with SUN.         *
 *                              Incorporated user interface for       *
 *                              specifying sound file names.          *
 *                              Also incorporated user interface for  *
 *                              writing AIFF compatible sound files.  *
 * 27jun91  dpwe (Aware)        Added musicout and &sample_frames as  *
 *                              args to out_fifo (were glob refs).    *
 *                              Used new 'frame_params' struct.       *
 *                              Clean,simplify, track clipped output  *
 *                              and total bits/frame received.        *
 * 7/10/91  Earle Jennings      changed to floats to FLOAT            *
 *10/ 1/91  S.I. Sudharsanan,   Ported to IBM AIX platform.           *
 *          Don H. Lee,                                               *
 *          Peter W. Farrett                                          *
 *10/ 3/91  Don H. Lee          implemented CRC-16 error protection   *
 *                              newly introduced functions are        *
 *                              buffer_CRC and recover_CRC_error      *
 *                              Additions and revisions are marked    *
 *                              with "dhl" for clarity                *
 * 2/11/92  W. Joseph Carter    Ported new code to Macintosh.  Most   *
 *                              important fixes involved changing     *
 *                              16-bit ints to long or unsigned in    *
 *                              bit alloc routines for quant of 65535 *
 *                              and passing proper function args.     *
 *                              Removed "Other Joint Stereo" option   *
 *                              and made bitrate be total channel     *
 *                              bitrate, irrespective of the mode.    *
 *                              Fixed many small bugs & reorganized.  *
 *19 aug 92 Soren H. Nielsen    Changed MS-DOS file name extensions.  *
 * 8/27/93 Seymour Shlien,      Fixes in Unix and MSDOS ports,        *
 *         Daniel Lauzon, and                                         *
 *         Bill Truerniet                                             *
 *--------------------------------------------------------------------*
 * 4/23/92  J. Pineda           Added code for layer III.  LayerIII   *
 *          Amit Gulati         decoding is currently performed in    *
 *                              two-passes for ease of sideinfo and   *
 *                              maindata buffering and decoding.      *
 *                              The second (computation) pass is      *
 *                              activated with "decode -3 <outfile>"  *
 * 10/25/92 Amit Gulati         Modified usage() for layerIII         *
 * 12/10/92 Amit Gulati         Changed processing order of re-order- *
 *                              -ing step.  Fixed adjustment of       *
 *                              main_data_end pointer to exclude      *
 *                              side information.                     *
 *  9/07/93 Toshiyuki Ishino    Integrated Layer III with Ver 3.9.    *
 *--------------------------------------------------------------------*
 * 11/20/93 Masahiro Iwadare    Integrated Layer III with Ver 4.0.    *
 *--------------------------------------------------------------------*
 *  7/14/94 Juergen Koller      Bug fixes in Layer III code           *
 **********************************************************************/

#include        "common.h"
#include        "decoder.h"

/********************************************************************
/*
/*        This part contains the MPEG I decoder for Layers I & II.
/*
/*********************************************************************/

/****************************************************************
/*
/*        For MS-DOS user (Turbo c) change all instance of malloc
/*        to _farmalloc and free to _farfree. Compiler model hugh
/*        Also make sure all the pointer specified are changed to far.
/*
/*****************************************************************/

/*********************************************************************
/*
/* Core of the Layer II decoder.  Default layer is Layer II.
/*
/*********************************************************************/

/* Global variable definitions for "musicout.c" */

char *programName;
int main_data_slots();
int side_info_slots();

/* Implementations */

main(argc, argv)
int argc;
char **argv;
{
/*typedef short PCM[2][3][SBLIMIT];*/
typedef short PCM[2][SSLIMIT][SBLIMIT];
    PCM FAR *pcm_sample;
typedef unsigned int SAM[2][3][SBLIMIT];
    SAM FAR *sample;
typedef double FRA[2][3][SBLIMIT];
    FRA FAR *fraction;
typedef double VE[2][HAN_SIZE];
    VE FAR *w;

    Bit_stream_struc  bs;
    frame_params      fr_ps;
    layer             info;
    FILE              *musicout;
    unsigned long     sample_frames;

    int               i, j, k, stereo, done=FALSE, clip, sync;
    int               error_protection, crc_error_count, total_error_count;
    unsigned int      old_crc, new_crc;
    unsigned int      bit_alloc[2][SBLIMIT], scfsi[2][SBLIMIT],
                      scale_index[2][3][SBLIMIT];
    unsigned long     bitsPerSlot, samplesPerFrame, frameNum = 0;
    unsigned long     frameBits, gotBits = 0;
    IFF_AIFF          pcm_aiff_data;
    char              encoded_file_name[MAX_NAME_SIZE];
    char              decoded_file_name[MAX_NAME_SIZE];
    char              t[50];
    int               need_aiff;
    int               need_esps;        /* MI */
    int topSb = 0;

III_scalefac_t III_scalefac;
III_side_info_t III_side_info;

#ifdef  MACINTOSH
    console_options.nrows = MAC_WINDOW_SIZE;
    argc = ccommand(&argv);
#endif

    /* Most large variables are declared dynamically to ensure
       compatibility with smaller machines */

    pcm_sample = (PCM FAR *) mem_alloc((long) sizeof(PCM), "PCM Samp");
    sample = (SAM FAR *) mem_alloc((long) sizeof(SAM), "Sample");
    fraction = (FRA FAR *) mem_alloc((long) sizeof(FRA), "fraction");
    w = (VE FAR *) mem_alloc((long) sizeof(VE), "w");

    fr_ps.header = &info;
    fr_ps.tab_num = -1;                /* no table loaded */
    fr_ps.alloc = NULL;
    for (i=0;i<HAN_SIZE;i++) for (j=0;j<2;j++) (*w)[j][i] = 0.0;

    programName = argv[0];
    if(argc==1) {        /* no command line args -> interact */
       do {
          printf ("Enter encoded file name <required>: ");
          gets (encoded_file_name);
          if (encoded_file_name[0] == NULL_CHAR)
             printf ("Encoded file name is required. \n");
       } while (encoded_file_name[0] == NULL_CHAR);
       printf (">>> Encoded file name is: %s \n", encoded_file_name);
#ifdef  MS_DOS
       printf ("Enter MPEG decoded file name <%s>: ",
               new_ext(encoded_file_name, DFLT_OPEXT)); /* 92-08-19 shn */
#else
       printf ("Enter MPEG decoded file name <%s%s>: ", encoded_file_name,
               DFLT_OPEXT);
#endif
       gets (decoded_file_name);
       if (decoded_file_name[0] == NULL_CHAR) {
#ifdef  MS_DOS
           /* replace old extension with new one, 92-08-19 shn */
           strcpy(decoded_file_name,new_ext(encoded_file_name, DFLT_OPEXT));
#else
           strcat (strcpy(decoded_file_name, encoded_file_name), DFLT_OPEXT);
#endif
       }
       printf (">>> MPEG decoded file name is: %s \n", decoded_file_name);

       printf(
          "Do you wish to write an AIFF compatible sound file ? (y/<n>) : ");
       gets(t);
       if (*t == 'y' || *t == 'Y') need_aiff = TRUE;
       else                        need_aiff = FALSE;
       if (need_aiff)
            printf(">>> An AIFF compatible sound file will be written\n");
       else printf(">>> A non-headered PCM sound file will be written\n");

       printf(
          "Do you wish to exit (last chance before decoding) ? (y/<n>) : ");
       gets(t);
       if (*t == 'y' || *t == 'Y') exit(0);
    }
    else {        /* interpret CL Args */
       int i=0, err=0;

       need_aiff = FALSE;
       need_esps = FALSE;	/* MI */
       encoded_file_name[0] = '\0';
       decoded_file_name[0] = '\0';

       while(++i<argc && err == 0) {
          char c, *token, *arg, *nextArg;
          int  argUsed;

          token = argv[i];
          if(*token++ == '-') {
             if(i+1 < argc) nextArg = argv[i+1];
             else           nextArg = "";
             argUsed = 0;
             while(c = *token++) {
                if(*token /* NumericQ(token) */) arg = token;
                else                             arg = nextArg;
                switch(c) {
                   case 's':  topSb = atoi(arg); argUsed = 1;
                      if(topSb<1 || topSb>SBLIMIT) {
                         fprintf(stderr, "%s: -s band %s not %d..%d\n",
                                 programName, arg, 1, SBLIMIT);
                         err = 1;
                      }
                      break;
                   case 'A':  need_aiff = TRUE; break;
                   case 'E':  need_esps = TRUE; break;	/* MI */
                   default:   fprintf(stderr,"%s: unrecognized option %c\n",
                                      programName, c);
                      err = 1; break;
                }
                if(argUsed) {
                   if(arg == token) token = ""; /* no more from token */
                   else             ++i; /* skip arg we used */
                   arg = ""; argUsed = 0;
                }
             }
          }
          else {
             if(encoded_file_name[0] == '\0')
                strcpy(encoded_file_name, argv[i]);
             else
                if(decoded_file_name[0] == '\0')
                   strcpy(decoded_file_name, argv[i]);
                else {
                   fprintf(stderr,
                           "%s: excess arg %s\n", programName, argv[i]);
                   err = 1;
                }
          }
       }

       if(err || encoded_file_name[0] == '\0') usage();  /* never returns */

       if(decoded_file_name[0] == '\0') {
          strcpy(decoded_file_name, encoded_file_name);
          strcat(decoded_file_name, DFLT_OPEXT);
       }

    }
    /* report results of dialog / command line */
    printf("Input file = '%s'  output file = '%s'\n",
           encoded_file_name, decoded_file_name);
    if(need_aiff) printf("Output file written in AIFF format\n");
    if(need_esps) printf("Output file written in ESPS format\n"); /* MI */

    if ((musicout = fopen(decoded_file_name, "w+b")) == NULL) {
       printf ("Could not create \"%s\".\n", decoded_file_name);
       exit(1);
    }

    open_bit_stream_r(&bs, encoded_file_name, BUFFER_SIZE);

    if (need_aiff)